<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>立即调用函数表达式</title>
</head>
<body>
<script>
    function func() {
        console.log("output from func");
    }

    func()

    let f = function () {
        console.log("output from anonymous");
    }

    f();
    (f)();

    (function () {
        console.log("output from anonymous");
    })();

    (function () {
        console.log("output from anonymous");
    }())

</script>
</body>
</html>